Nozzles selectively emit various types of materials, such as and without limitation a liquid material such as paint, thereby allowing the selectively emitted material to be placed or deposited upon various objects and/or targeted locations in some desired pattern and/or concentration. Particularly, the paint, or other type of liquid material, is atomized by a relatively high velocity stream of gas which traverses the generally hollow nozzle, thereby creating atomized particles or droplets of material. These atomized material particles or droplets are then selectively emitted from the exit or outlet aperture of the nozzle, along with the atomizing gas, and impinge upon and adhere to the targeted object or location. It is often times desirable to cause the material to be deposited upon the targeted object and/or location in a substantially uniform concentration (i.e., the concentration of the applied material along and/or throughout the entire material deposition region or area is substantially constant or uniform). In this manner, the deposited material forms an overall aesthetically pleasing appearance and allows for the desired and selective formation of substantially "clean", "crisp", and substantially straight edges. Moreover, it is desirable to substantially ensure that the emission velocity of the atomized material is substantially uniform and/or constant in order to allow the material emission device and/or nozzle to be placed or held at a certain distance from the targeted object and/or location, effective to cause all of the atomized material to impinge upon the targeted object and/or location at a certain substantially identical velocity without causing undesired spattering and/or non-uniform deposition concentrations.
While prior nozzles and nozzle assemblies selectively emit material and allow the selectively emitted material to be placed upon various objects and/or targeted locations (e.g., a vehicle), they do not readily provide for the deposition of substantially uniform material concentrations upon the object and/or location, do not substantially allow for the desired formation of relatively "crisp", "clean", and straight edges, and do not substantially ensure that all of the atomized material emanates from the nozzle at a substantially identical velocity.
These drawbacks are primarily due to the creation of relatively turbulent shear layers which are typically created and/or formed along the edges of the emitted gas, thereby causing the velocity of the gas, which is emitted at, through, and along the edges of the nozzle outlet aperture, to exponentially decay, thereby causing and/or creating a non-uniform velocity profile within the nozzle outlet aperture (i.e., the velocity of the gas which is emitted at and/or through the center portion of the nozzle outlet or exit aperture is substantially larger or greater than the velocity of the gas which is emitted at or along the edges of the outlet aperture).
The shear layer and its concomitant creation of a non-uniform velocity profile, similarly causes different amounts and/or quantities of the atomized material to be emitted along and through the exit or outlet and to form or create non-uniform deposition concentration regions upon the portion of the targeted object or location to which the atomized material is applied. That is, the relatively high velocity atomizing gas, which is emitted along and/or through the middle or center portion of the nozzle outlet , aperture, causes greater amounts of atomized material to be emitted along or through this middle portion of the nozzle outlet aperture, and causes more of the atomized material to be deposited upon the portion of the target object/location which receives the material through this center or middle aperture portion. The non-uniformity of the emitted atomizing gaseous material also causes the atomized material to have a nonuniform velocity (i.e., the atomized particles are not emitted from the nozzle at a substantially identical velocity and impinge upon the targeted location and/or object at different velocities).
There is therefore a need for a new and improved nozzle which allows material, such as paint, to be selectively atomized and deposited upon a targeted location and/or object; which allows for the deposited material to have a substantially uniform deposition concentration; and which allows for the formation of relatively "clean", "crisp", and straight edges; which allows the atomizing material to have a substantially uniform velocity profile along and/or throughout the material outlet or exit aperture; and which allows the atomized material to have a substantially uniform impingement velocity profile.